Question

Explain the process of digestion of food in human body and where it happens???

Answer 1

Digestion of food occurs in following ways in:Mouth (Buccal cavity) The mouth contains teeth, which crushes the food into small particles. Salivary glands present in the mouth secretes saliva which moistens the food. It also contains enzyme salivary amylase, that acts as



(ii) Stomach Gastric glands are present in the wall of the stomach which releases the following secretions:
(a) Hydrochloric acid To make the medium acidic for the action of enzyme pepsin.
(b) Mucus To protect the inner lining of the stomach from the action of acid.
© Pepsin A protein digesting enzyme.



(iii) Small intestine It is the site of complete digestion of carbohydrates, proteins and fats.
It receives secretions from liver and pancreas.

(a) Bile juice It is secreted by liver and performs the following functions :
It makes the medium alkaline for the pancreatic enzymes to act and also breaks down large fat globules into smaller globules.
(b) Pancreatic juice It is secreted by pancreas. Contains enzymes like amylase for digesting starch, trypsin for digesting proteins and lipase for breaking down emulsified fats.
© Intestinal juice It is secreted by the walls of small intestine. Contains a number of enzymes such as maltase, lipase etc., for complete digestion.

Answer 2

■ MOUTH:-

♤ FLUID CALLED SALIVA SECRETED BY THE SALIVARY GLANDS.

♤ THE SALIVA CONTAINS AN ENZYME CALLED SALIVARY AMYLASE.

♤ FUNCTION :- BREAK DOWN STARCH INTO COMPLEX MOLECULE TO GIVE SUGAR.

HELP IN MOISTENS THE FOOD EASY FOR CHEWING AND SWALLOWING

■ OESOPHAGUS:-

♤ THE CANAL HAS MUSCLES THAT CONTRACT RHYTHMICALLY TO PUSH THE FOOD FORWARD & THIS MOVEMENT OF FOOD IS CALLED PERISTALTIC MOVEMENT WHICH OCCURS ALONG THE G.UT.

■ STOMACH:-

♤ GASTRIC GLANDS ARE PRESENT IN STOMACH.

♤ IT RELEASE HYDROCHLORIC ACID (HCL).

♤ FUNCTION:- KILL HARMFUL BACTERIA THAT ENTERS WITH THE FOOD.

MAKES THE MEDIUM ALKALINE.

♤ PEPSIN:- THEY ARE PROTEIN DIGESTED ENZYME.

♤ MUCUS:- PROTECTS THE INNER LINING OF THE STOMACH FROM THE ACTION OF HYDROCHLORIC ACID.

■ SMALL INTESTINE:-

♤ THE EXIT OF FOOD FROM THE STOMACH IS REGULATED BY A SPHINCTER MUSCLE.

♤ IT HELPS IN DIGESTION OF CARBOHYDRATES, PROTEINS AND FATS.

■ LIVER :- IT SECRETE BILE JUICE IN GALL BLADDER.

♤ FUNCTION:- TURN ACIDIC MEDIUM TO ALKALINE.

EMULSIFY THE ACTION OF FAT.

♤ PANCREAS:- IT SECRETE PANCREATIC JUICE IT CONTAIN ENZYME LIKE:-

♤ TRYPSIN :- HELPS IN BREAK DOWN OF PROTEINS.

♤ LIPASE :- CONVERT FAT INTO FATTY ACID AND GLYCEROL.

■ INTESTINAL JUICE:- THE WALL OF SMALL INTESTINE CONTAIN GLAND WHICH SECRETE INTESTINAL JUICE.

♤ FUNCTION :- CONVERT PROTEINS TO AMINO ACIDS.

♤ COMPLEX CARBOHYDRATES INTO GLUCOSE.

♤ FATS INRO FATTY ACIDS AND GLYCEROL.

■ VILLI:- THE INNER LINING OF THE SMALL INTESTINE HAS NUMEROUS FINGER LIKE PROJECTIONS CALLED VILLI.

♤ FUNCTION:- INCREASE THE SURFACE AREA FOR ABSORPTION.

THEY ARE RICHLY SUPPLIED WITH BLOOD VESSELS WHICH TAKE THE ABSORBED FOOD TO EACH AND EVERY CELL OF THE BODY

■ LARGE INTESTINE:-

THE EXIT OF WASTE MATERIAL FROM THE BODY IS REGULATED BY THE ANAL SPHINCTER.